Update redirects for Christmas Meal (#857)

Removed old BBQ and EPS trophy redirects and added new Christmas-related redirects.

Signed-off-by: Matty Widdop <[email protected]>

Author: MattyTheHacker

_redirects

@@ -93,7 +93,7 @@
 
 /supervisor-opinions https://docs.google.com/document/d/1jyzgp8ScrmvVpf8k0EplTuvflxqqbcY3LJoQX0Tg8jc/
 
-/bbq-allergies https://forms.gle/pwygMk3M9kpBrGro7
-/bbq https://www.guildofstudents.com/events/6531/11174/
-
-/eps-trophy https://docs.google.com/forms/d/e/1FAIpQLSeeOkrUo24JrkafsJryeBTkQM750MiFMWKkUTPUASwMZrNigQ/viewform?usp=header
+/christmas https://www.guildofstudents.com/events/6531/11884/
+/christmas-meal /christmas
+/xmas /christmas
+/xmas-meal /christmas